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Help me decide: carb improvements & brakes

3K views 38 replies 9 participants last post by  bscott2231 
#1 ·
Howdy,

I've been chasing down a slippery ghost with my carbs and I think it's that they wont stay in the damn boots. I'm sure this is because of poor clamping and such. Because I like to spend money (who doesn't) and make my Bonne more and more mine I'd like to get your opinion.

1) If I buy the TPUSA billet intake boots will that solve all of my vacuum leak and slippy boot issues? Are there any other actual benefits besides completely eliminating the vacuum leaks from clamps and boots?

https://newbonneville.com/shop/billet-intake-manifolds/

2) What about the FCR 39 carbs? They look pretty amazing and since my bike is already opened up with the TPUSA kit (doms) and Carlos would send me a kit that is tuned for my bike (we are like 100 miles apart) that would be a great bolt on. Are there any real benefits here besides the extra tuneability, added RWHP? Can I anticipate any change in fuel economy? I'm assuming worse but who knows.

http://www.triumphperformanceusa.com/index.php?main_page=product_info&cPath=7&products_id=7

3) What about other carbs? I see there are Kehnin 36mm racing carbs that are half as much as the FCR 39s. Any thoughts there?

On the brakes issues, I think the rotors on the bike are original so that means they have about 24k miles on them. The pads are all new. The calipers are original. When I rebuilt my wiring harness (mUnit) I installed 7/8" handlebars so I install a Street Triple 11mm front master cylinder that I've never been happy with. There is no 'action' in the braking, very little room maybe 1/4-1/2" between no brake, some brake and fully locked. The brake also locks up from time to time if I've been running and braking for a while. I just flushed and filled it again yesterday so I'm riding it around to see if I've figured that bit out.

Anyway, what do you think or recommend for a reasonable replacement of front calipers and brakes? What about rear?

These look good for fronts and within my price range. Would I have to change the master cylinder again?

https://newbonneville.com/shop/brembo-rotor-and-caliper-brake-kit/

Thanks as always for your excellent input!
 
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#2 ·
3) What about other carbs? I see there are Kehnin 36mm racing carbs that are half as much as the FCR 39s. Any thoughts there?

On the brakes issues
Anyway, what do you think or recommend for a reasonable replacement of front calipers and brakes? What about rear?
My opinion for # 3 is that Keihin Cr's work great with the air box
and exhaust changes you have made. The only difference with my set up is I'm using Uni filter instead on K+N's. Plus you save a ton of money, also sometimes they are avail used.

Now for the brakes, are you rotors still within factory specs ?
If they are why replace them, unless your after looks.... I've replaced my pads with EBC HH double sintered pads. They work much better than stock pads and last A LOT longer. Again you would be saving ton's of money. The stock rear brakes wear out quickly, I replaced them with EBC's also.
 
#3 ·
Thanks wenzel! Did you realize any MPG improvements using the Keihin CRs? What kind of other improvements would you say you've experienced?
 
#4 ·
To upgrade my front brakes I fitted a Newfren floating rotor and EBC HH pads. The EBC pads are known for being grabby, which works well for a motorcycle with a single disc brake because they have much better bite. They also have much more stopping power. This combination is very impressive when you want to stop in a hurry.

The stock, one-piece front rotor has a tendency to warp which floating rotors don't do, while the slots in the stock rotor tear at the pads and wear them down too fast.

I left my rear brake stock. It has enough power to lock the back wheel without that much effort, so that's good enough for me.
 
#6 ·
As for the brakes. I went with replacing the caliper with a Nissin 6 pot from a Honda Trans Alp, EBC floating disc and pads. The difference is night and day the whole lot cost approx. £220 and that was with a new old stock caliper. There are many threads on the subject and if I new what the hell I was doing I would attach a link.
 
#8 ·
I have the Brembo kit on my T100. I upgraded to a Speedmaster 1/2 inch m/cylinder but wasn't really happy until I changed the pads for a set of sintered Ferodo's. On my America I have a 6 pot Berringer with a 14mm Rocket 3 m/cylinder and EBC floater, works great. T100 has solo seat and America is for riding two up and am happy with brakes on both now.
 
#9 · (Edited)
I ended up scoring what I believe to be the correct 3-pot Honda CB600 left hand caliper (and right if anyone wants to buy it) from eBay in UK! Excited.

What's a good and affordable front rotor here? Is there a specific size I should be shooting for?

Also, any more words on the carb issues? I think I am ruling out the FCRs because they are just too expensive. The CR Racing ~ $799 are more affordable. How tuneable are they? Are they essentially bolt on? Assuming NewBonneville can jet them for sea level and my current configuration? Do they use the standard jets (physical dimensions of the jets)?

What's the big difference between the FCR ($1500) and the CRs ($800)? They both look to have the aluminum boots on the intake and throttle bodies.

Any worries on the push/pull throttle wires? Do I need to replace those?
 
#10 ·
Lossa still has a few sets of FCR39s at old pricing. May make decision easier for you.
http://www.lossaengineering.com/col...products/keihin-cr-roundslide-special-carbs-1

Link says cr carbs but they are actually FCRs

When I upgraded to FCR39s, I also debated the CRs. At that time pricing was closer but everyone hands down said go with the FCRs and I am glad I did. To this day, it is still the favorite mod on my bike. It really transforms how the bike delivers the power.
 
#11 ·
Even without opening up the head or any of the other major engine mods?
 
#14 ·
Just double checked my master. It's an 11mm; so, I should be good to go, no?

How difficult are the FCR's to tune?
 
#16 ·
When I installed my 6 pot Berringer on my 2002 America I tried it with the stock 11 mm M/C and it worked better than the stock brakes, but there was a lot of travel in the lever and I had to give a good pull on it. Installed a 14 mm Rocket III M/C and the lever is great, no drama and can modulate with ease. FWIW the 14 mm was too big for my 4 pot Brembo kit, 1/2 inch Speedy one works great.
The O.P. should be fine with an 11 mm M/C if he uses a 3 pot caliper.
 
#17 ·
Wonderful news. I've gone through a ton of drama with this brake in the conversion to 7/8" from 1" bars. I'm hoping that the 3-pot caliper takes away all this 'woody' feeling I'm getting. As I understand it, air bubbles in the brake line would make the brake action feel 'squishy', right? I'm far from that. It's more like 'woody' or 'hard'. The brake lever has almost no travel from no brake to fully stopped.

*Fingers crossed* that a completely new caliper, new brake lines and a fresh bleed with new fluid cures my front brake woes. I'm still shopping for a good front rotor. Everything seems to be insanely expensive but I guess they last for almost-ever so that's a good investment.
 
#24 ·
So what kind of wide band O2 monitor do you recommend? It has to be welded into the header right? The MC is definitely 11mm I must have mistyped earlier.
 
#25 ·
Innovate has a few different models of a Wide Band O2 Monitor.
Their best/most useable models include Data Recording.

I forget the model number that I have, but it utilizes dual O2's (one for each cylinder) and includes Data Recording.
You can also get an Optional Auxiliary Caple for inputting a Tach Signal (RPM), and TPS (Throttle Angle) ..... most helpful when analyzing data.
Recording the Data is very helpful. You can just make appropriate "runs" while "recording"......... then Download and Review on a Computer of choice.
Much better than trying to read a gauge while getting a handful on the road.

Yes, you will need to weld an "O2 bung" into the exhaust system to accept a 14mm Wide Band O2 Sensor. Ideally TWO ..... one in each pipe, above the Crossover pipe (if you run one) .
 
#26 ·
This is all great information, thanks team. I have been reading this thread 'To FCR or not' @ http://www.triumphrat.net/air-cooled-twins-technical-talk/547401-to-39-or-not-to-39-a-3.html and it is super enlightening. It seems like getting the ignition timing advanced and then cams makes more sense before going to the FCR.

What is this ignition timing they keep referring to? I cannot find any good intro posts or walk throughs. I know I must be missing something. Any ideas on what could be good with my bike?
 
#27 ·
Well I gone and dun it!

Here is what is currently speeding its way to me:

FCR 39mm carbs from Lossa Engineering (new 3/16" ID fuel lines to boot)
TTP Fire Starter Stage 1 from PieMan
Billet intake manifolds from TPUSA
Nissin 3-pot caliper from the UK also with new EBC HH pads
New Spiegler front and rear brake lines to replace the stock dealies
Barnett Clutch Green Springs and a new gasket
4 quarters of Redline synethatic
K&N oil filter

What's next (next year)

Polished aluminum front and rear fenders (can't find any I really like for the rear). The Motone front fender looks killer.
Kineo black matte tubeless wheels (3.5 x 17 front, and 4.25 x 17 rear)
Some more aggressive treaded tires
 
#31 ·
Well .......... sounds like you are about to embark on an intimate engagement with your ride.
While nothing is more enjoyable than simply "riding it" .............. it can also be said that their is no replacement for the feelings of "satisfaction" that come from improving things yourself!

When you get it set up ............ the difference will similar to getting rid of the old brunette GF, and replacing her with a new naughty redhead GF.>:):wink2:

"Suddco" (sp?) has all the parts you need, on hand, for tuning the FCR's.
They have on line, downloadable, catalog.

I have a link ................ if I can find it, I will post it.
Otherwise, a search should yield results.

And when you get her set up ................. don't slap her a*s, unless you are ready for a ride!
No Viagra needed.0:)
 
#28 ·
Can anyone recommend a place to buy extra jets and needles and such for the FCR 39? I can't seem to find any online.
 
#29 ·
Factory Pro in San Rafael has jets.

Having recently done these mods, the only time I regret it is in the mountains. If you tune it for sea level and always ride at sea level, you're golden. That's a secret I did not know before I pulled the trigger. Whereas the the CVK's compensate and run "okay" through a wider range of elevations, the FCR's run out of breath when you climb too high. You start noticing it as early as 2000 feet.
 
#30 ·
Thanks Steve. I riding pretty much only sea level or as high as 500' the majority of the time. It's mostly city riding, commuting and coastal cruising.

After reading through these threads this looks like it could be a good starting point

135 mains
52 pilots
EMR needles (3rd clip)
200 main airs
 
#33 ·
Right jets?

Can someone tell me if these are the right type main and jet carbs? Where can I get main airs?
 

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#34 ·
Can someone tell me if these are the right type main and jet carbs? Where can I get main airs?
I will check tomorrow for you.
Down for the day.

The mains look about right, not positive on the Slow Jets.... but they look familiar, although they may be familiar to another model carb.
Again, I will check my kit and confirm.

The Air Jet is an adjustable type, but there are "Fixed Orifice" jets available if you so desire. Although there is no reason for them. I've not had/read about them vibrating out of adjustment, so all is good.
 
#37 ·
Here are the default FCR 39 settings

The guy from Lossa engineering says they are pre-jetted as follows:

155 mains
55 pilots
FKR needdles
200 main airs

Any thoughts on this?
 
#39 ·
Sorry, forgot to look at my jets today........... moot point now anyway I suppose.

"I" cannot help on jetting on a stock engine, as mine is not.
An A/F Data Logger, or gauge, will tell you where you are at though.

Sounds like Soutofheaven just gave you a baseline jet recommendation ("as they come"), but every bike is a bit different.
Don't trust someone else's final settings for YOUR bike, there will be a difference .......... even if it is subtle. Use an A/F unit.

Have fun with it!
 
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